At least eight Hanoi parishioners had been arrested since mid-August when Catholics started their latest round of protests for the return of church lands confiscated by the state since the 1950s, said Human Rights Watch (HRW).

The group said authorities had used tear gas and electric batons to disband protesters and that “hundreds of unidentified thugs, some in the blue shirts of the Communist Youth League” had harassed and spat at parishioners.

“This is the harshest crackdown on Catholics in Vietnam in decades,” said Elaine Pearson, deputy Asia director of Human Rights Watch.

“Sadly, religious repression and violent crackdowns by the Vietnamese authorities against peaceful protesters are nothing new.”

The New York-based group also urged the government “to end the harassment, threats and restrictions on the movement of the Archbishop of Hanoi, Joseph Ngo Quang Kiet,” who has been at the centre of the protests.

The government was running “an intense smear campaign against Archbishop Kiet” in the state-controlled media, accusing him of illegal and unpatriotic acts by instigating the prayer vigils, HRW said.

The government has in recent weeks sought to end the disputes by building public parks at the two disputed Hanoi sites, the Vatican’s former embassy near Hanoi’s main St. Joseph Cathedral, and the Thai Ha Redemptorist church.

Last week Prime Minister Nguyen Tan Dung met Catholic bishops and warned them the government would not tolerate the mass vigils in which Catholics had broken the law and illegally entered the disputed properties.

Vietnam, a unified communist country since the war ended in 1975, has Southeast Asia’s largest Catholic community after the Philippines – at least six million out of a population of 86 million.

Religious activity remains under state control, but Hanoi’s relations with the Catholic Church had improved, leading to Dung making a landmark visit to the Vatican in 2007, before the recent wave of protests.

HRW’s Pearson said: “The government should support religious tolerance and peaceful assembly instead of using the media to vilify religious leaders and paint peaceful religious protesters as a menace to the public.”The Times – Vietnam must free Catholics: Rights group